Amazon.com Search Box on Navbar
 

I recently visited a message board that had a "Shop with Amazon" drop down menu on the top of their forum (navigation bar area). When users click on this link, a small search box (similar to the “Search Forum” and "Arcade Search" box, except it would go to an amazon.com page) with an amazon logo and design appears, in where users would enter their query in the search-like box. For example, a member would type in a product name and it would automatically take them to the corresponding amazon.com page.

I was wondering how I would be able to install this feature onto my message board. Please try to be very thorough and detailed when describing the steps and the coding involved.